Supporting roles refer to characters in a play or movie who play a secondary role to the protagonist or lead character. Synonyms for supporting roles include secondary, minor, subsidiary, or backup characters. These characters often support or complement the main character's story and help to move the plot forward. Other similar phrases to describe these characters can include allies, assistants, or companions. These roles are important in adding depth to the story and character development. Additionally, supporting characters can be used to provide comedic relief, offer moral guidance, or add dramatic tension. Overall, supporting roles are crucial in creating a well-rounded and interesting story.